The study area is the forest “Ratośniówki”, which is located in the town of Strzyżów in the Strzyżowskie Foothills (30 km in SW of Rzeszów, 49°52 ́N, 21°47 ́E, ATPOL grid square FF8310). The floristic investigations carried out in 2008–2010 resulted in the list of vascular plant species and the assessment of human impact exerted on vegetation. Among 209 species found in the area 17 mountain species have been recorded: Abies alba, Aposeris foetida, Dentaria glandulosa, Lysimachia nemorum, Petasites albus, Polistichum aculeatum, Salvia glutinosa, Sambucus racemosa,Senecio nemorensis, Senecio ovatus, Stachys alpina, Symphytum cordatum, Veronica montana, Dryopteris dilatata,Scilla bifolia, Scilla kladnii, Equisteum telmateia, 17 protected species (11 fully protected, 6 partially protected): Centaurium erythraea, Cephalanthera damasonium, Cephalanthera longifolia, Daphne mezereum, Galanthus nivalis, Neottia nidus-avis, Platanthera bifolia, Polypodium vulgare, Polystichum aculeatum, Scilla bifolia, Staphyllea pinnata, Asarum europaeum, Frangula alnus, Galium odoratum, Hedera helix, Primula elatior, Viburnum opulusand 3 species listed in the “Red List of Poland” (Zarzycki, Szelag 2006): Cephalanthera damasonium, Cephalanthera longifolia, Polystichum aculeatum. The investigated forest area represents the association of Tilio-Carpinetum. The forest stands are characterised by a high degree of naturalness as indicated by a large proportion of old-growth forests’ species (61 species, accounting for 30% of the flora) and examples of trees as natural monuments. The forest “Ratośniówki” is the most valuable in the whole area of Strzyżów and needs to be protected due to natural, cultural and landscape values.